[Cardioprotective Effect and Its Mechanism of Total Saponins of Panacis Majoris Rhizoma in Myocardial Infarction Rats].

OBJECTIVE: To explore the cardioprotective effect and its mechanism of total saponins of Panacis Majoris Rhizoma in myocardial infarction (MI) rats. METHODS: The MI model rats induced by ligating anterior descending branch of coronary artery were randomly divided into four group:model group, total saponins of Panacis Majoris Rhizoma (100 and 200 mg/kg) groups and compound Danshen dripping pills group. The rats were orally administrated with drugs once a day for four weeks. Another rats were selected as sham operation group. After four weeks intervention, cardiac function was examined, the serum levels of TNF-α, IL-1ß, IL-6 and IL-8 were measured by using ELISA, respectively. The myocardial hypertrophy index was investigated, the myocardial infarct size, degree of ventricular dilatation, myocardial interstitial collagen volume fraction and tissue morphology were investigated by HE, Masson, picric acid-sirius red staining and observing with alight microscope and electron microscope. Protein expressions of phosphorylation IκB-α( pIκB-α) and NF-κB p65 in heart tissue were detected by Western blotting. RESULTS: Total saponins of Panacis Majoris Rhizoma might significantly decrease the levels of serum TNF-α, IL-1ß, IL-6 and IL-8; decrease myocardial hypertrophy indexes, myocardial infarct size, degree of ventricular dilatation and myocardial interstitial collagen volume fraction; improve heart tissue morphology and cardiac function; downregulate protein expression of pIκB-α and NF-κBp65; and upregulate protein expression of SIRT1. The aforementioned action effects of total saponins of Panacis Majoris Rhizoma (200 mg/kg) were similar with compound Danshen dripping pills. CONCLUSION: Total saponins of Panacis Majoris Rhizoma possesses cardioprotective effect against ligating left anterior descending branch induced MI in rats. The mechanism may be related to strengthening SIRT1 expression, inhibiting the phosphorylation of IκB-α, and finally inhibiting the activation of NF-κB and proinflammatory production.

Resveratrol inhibits right ventricular hypertrophy induced by monocrotaline in rats.

1. Resveratrol (RSV), a polyphenol in red wine, exhibits cardioprotective effects in vitro, such as inhibition of angiotensin II- or phenylephrine-induced cardiomyocyte hypertrophy in rat neonatal myocyte cultures and suppression of cardiac fibroblast proliferation. The aim of the present study was to investigate the protective effects of RSV against monocrotaline (MCT)-induced right ventricular (RV) hypertrophy in rats. 2. Male Sprague-Dawley rats were given a single injection of MCT (50 mg/kg, s.c.) and were then treated with either vehicle (normal saline) or RSV (10 and 30 mg/kg, i.g., twice daily) for 21 days. A separate group of control rats were not injected with MCT and were treated with normal saline for 21 days. At the end of the treatment period, all rats were subjected to echocardiography and haemodynamic measurements. In addition, after rats had been killed, the hearts were subjected to histopathological, untrastructural and immunohistochemical analyses. 3. In vehicle-treated rats, MCT injection resulted in 33% mortality, whereas mortality in RSV-treated MCT-injected rats was 0%. In vehicle-treated rats, MCT increased RV free wall thickness and RV systolic pressure and decreased pulmonary arterial acceleration time at the end of the experimental period. These dynamic changes were ameliorated by RSV in a dose-dependent manner. Histologically, MCT injection resulted in RV hypertrophy, swollen mitochrondria and cardiomyocyte apoptosis; all these morphological changes were dose-dependently improved in rats treated with RSV. 4. In conclusion, RSV inhibits the RV hypertrophy induced by MCT in rats and this effect is mediated by both a direct effect of RSV on cardiomyocytes and an indirect effect mediated via a reduction in pulmonary hypertension.

Galphaq-protein carboxyl terminus imitation polypeptide (GCIP)-27 inhibits right ventricular hypertrophy induced by monocrotaline in rats.

This study was to investigate the probable inhibitory effect of Galphaq-protein carboxyl terminus imitation polypeptide-27 (GCIP-27), the optimized form of GCIP, which is a competition candidate of the activated binding sites on Galphaq, on the right ventricular (RV) hypertrophy induced by monocrotaline (MCT) in rats. We have previously shown that GCIP-27, can prevent the hypertrophyc responses in cultured rat cardiomyocytes induced by noradrenaline and angiotensin II. Male Sprague-Dawley rats were given a single dose (50 mg/kg) of MCT subcutaneouly to induce pulmonary hypertension (PH) and RV hypertrophy. GCIP-27 (30, 90 microg/kg) or vehicle was administered (twice daily, intraperitoneally) from day 1 to day 21. GCIP-27 (90 microg/kg) inhibited the elevated pulmonary arteria systolic pressure (PASP) and mean pulmonary arteria pressure induced by MCT, but its dose at 30 microg/kg only reduced the elevated PASP. And no effect could be seen on the pulmonary arteria diastolic pressure at both two doses. On the other hand, the two doses of GCIP-27 improved significantly the weight ratio of RV to left ventricle plus septum, the RV free wall thickness and pulmonary arteria acceleration time (PAAT). In morphometric observation, GCIP-27 (30, 90g/kg) could attenuate cardiomyocytes hypertrophy, interstitium fibrosis, mitochondria swelling and malformation markedly in RVs of MCT-treated rats. Furthermore, GCIP-27 (30, 90 mug/kg) significantly reduced the overexpression of the proliferating cell nuclear antigen (PCNA) induced by MCT in RV cardiocytes. The results suggest that GCIP-27 can effectively attenuate the RV hypertrophy induced by MCT in rats, which may be mediated by both the direct effect on cardiomyocyte and the secondary effect by reducing PH, and may be involved in its influence on the Gq signal pathway.